For example, as described in Japanese Patent Application Laid-open No. 2003-170570, a cleaning unit provided in a screen printing apparatus according to the disclosure includes a cleaning head including a vacuum nozzle, a supply section configured to supply a cleaning sheet to an upper part of the cleaning head, and a winding roll for the cleaning sheet. The screen printing apparatus is configured to wipe off an applying material adhering to an opening section outer circumference or the like of the rear surface of a mask sheet (a screen) by advancing and retracting the cleaning unit in a state in which the cleaning sheet is brought into contact with the rear surface of the mask sheet and an attractive force is exerted by the cleaning head.
The screen printing apparatus includes a cleaning agent supplying device including a spraying nozzle or the like for a cleaning agent. The screen printing apparatus is configured to spray, during cleaning of the mask sheet, the cleaning agent supplied from a storing section for the cleaning agent on a section to be cleaned to thereby improve cleaning efficiency of the mask sheet by the cleaning sheet.
Spray work for the cleaning agent does not need to be performed every time a cleaning operation for wiping off the applying material is performed. The spray work for the cleaning agent may also be performed intermittently according to a need of a user. In this description, a cleaning operation performed using the cleaning agent is referred to as “wet type cleaning” and a cleaning operation performed without using the cleaning agent is referred to as “dry type cleaning”.
Incidentally, it is preferable to collect substantial residual quantities of consumable supplies such as the cleaning sheet. For such a purpose, a technique is widely used for various industrial products for detecting residual quantities of consumable supplies and, where the residual quantities are getting low, informing a user to that effect. For example, Japanese Patent Application Laid-open No. 2002-127454 discloses, residual quantity detection for an ink tank of an inkjet printer, a “sensor method” for detecting, with a sensor, a residual quantity of ink consumed as a consumable item, a “count method” for counting the number of times of use of the ink in one printing and multiplying a consumption of the consumable item per one printing estimated in advance with the number of times of use to thereby indirectly estimate a consumption of the ink, or a combined method of the “sensor method” and the “count method”.